Evaluating haemodynamic changes: vericiguat in patients with heart failure with reduced ejection fraction.

AIMS: Vericiguat has been used to treat patients with heart failure with reduced ejection fraction (HFrEF) who demonstrated worsening heart failure despite treatment with other guideline-directed medical therapies. The haemodynamic effects of vericiguat remain unclear. METHODS AND RESULTS: This study enrolled 12 patients (median age, 63 [quartiles 53.5, 70] years; 16.7%(N=2) women) with symptomatic HFrEF (New York Heart Association functional class II-IV) who demonstrated worsening heart failure despite treatment with the four foundational guideline-recommended therapies between March and December 2022, with follow-ups completed in June 2023. A balloon-tipped pulmonary artery thermodilution catheter was placed in the right internal jugular vein to perform right heart catheterisation (RHC) on day 1. Haemodynamic data were acquired before and after vericiguat intake (2.5 mg) on days 2 and 3. The data on days 2 and 3 were averaged. RHC was repeated on day 105 (37, 168). Oral intake of vericiguat 2.5 mg decreased mean pulmonary artery pressure (19.3 [14.3, 26.8] mmHg) and pulmonary artery wedge pressure (PAWP) (11 [7.5, 15] mmHg) before the intake to mean pulmonary artery pressure (17.5 [12.5, 24] mmHg) and PAWP (9.3 [6.8, 14] mmHg) at 30 min after (both P < 0.05). Reduction in PAWP was also found from 14.5 [9.5, 19.5] mmHg on day 1 to 9.5 [6.5, 12.5] mmHg on day 105 (37, 168) (P < 0.05), when vericiguat was titrated to 2.5 mg 25% (N = 3), 5 mg 50% (N = 6), and 10 mg 25% (N = 3). CONCLUSIONS: The consistent reduction in PAWP underscores the well-tolerated nature of vericiguat and its potential to enhance cardiac performance in patients with HFrEF.

von Willebrand factor Ristocetin co-factor activity to von Willebrand factor antigen level ratio for diagnosis of acquired von Willebrand syndrome caused by aortic stenosis.

Background: Severe aortic stenosis (AS) causes acquired von Willebrand syndrome by the excessive shear stress-dependent cleavage of high molecular weight multimers of von Willebrand factor (VWF). While the current standard diagnostic method is so-called VWF multimer analysis that is western blotting under nonreducing conditions, it remains unclear whether a ratio of VWF Ristocetin co-factor activity (VWF:RCo) to VWF antigen levels (VWF:Ag) of <0.7, which can be measured with an automated coagulation analyzer in clinical laboratories and is used for the diagnosis of hereditary von Willebrand disease. Objectives: To evaluated whether the VWF:RCo/VWF:Ag is useful for the diagnosis of AS-induced acquired von Willebrand syndrome. Methods: VWF:RCo and VWF:Ag were evaluated with the VWF large multimer index as a reference, which represents the percentage of a patient's VWF high molecular weight multimer ratio to that of standard plasma in the VWF multimer analysis. Results: We analyzed 382 patients with AS having transaortic valve maximal pressure gradients of >30 mmHg, 27 patients with peripheral artery disease, and 46 control patients free of cardiovascular disease with osteoarthritis, diabetes, and so on. We assumed a large multimer index of <80% as loss of VWF large multimers since 59.0% of patients with severe AS had the indices of <80%, while no control patients or patients with peripheral artery disease, except for 2 patients, exhibited the indices of <80%. The VWF:RCo/VWF:Ag ratios, measured using an automated blood coagulation analyzer, were correlated with the indices (rs = 0.470, P < .001). When the ratio of <0.7 was used as a cut-off point, the sensitivity and specificity to VWF large multimer indices of <80% were 0.437 and 0.826, respectively. Conclusion: VWF:RCo/VWF:Ag ratios of <0.7 may indicate loss of VWF large multimers with high specificity, but low sensitivity. VWF:RCo/VWF:Ag ratios in patients with AS having a ratio of <0.7 may be useful for monitoring the loss of VWF large multimers during their clinical courses.

Intractable Ventricular Tachycardia Prior to an Overt Cardiac Tumor Mass of Metastatic Cardiac Rhabdomyosarcoma (Spindle-cell Type).

We herein report a 37-year-old man who experienced recurrence of metastatic cardiac rhabdomyosarcoma along with intractable ventricular tachycardia (VT) 7 years after resection of rhabdomyosarcoma in his right elbow. At 36 years old, he developed VT unresponsive to radiofrequency catheter ablation (RFCA). Initially, the cardiac tumor was not detected, but it gradually grew in size at the RFCA site. A surgical biopsy confirmed the diagnosis of metastatic cardiac rhabdomyosarcoma. Despite radiation therapy, cardiac tumor progression and VT instability could not be prevented. Ultimately, the patient died 27 months after the initial documentation of VT.

Inhaled nitric oxide testing in predicting prognosis in pulmonary hypertension due to left-sided heart diseases.

AIMS: The pathophysiology of pulmonary hypertension (PH) due to left-sided heart disease (Group 2 PH) is distinct from that of other groups of PH, yet there are still no approved therapies that selectively target pulmonary circulation. The increase in pulmonary capillary pressure due to left-sided heart disease is a trigger event for physical and biological alterations of the pulmonary circulation, including the nitric oxide (NO)-soluble guanylate cyclase-cyclic guanosine monophosphate axis. This study investigated inhaled NO vasoreactivity tests for patients with Group 2 PH and hypothesized that these changes may have a prognostic impact. METHODS AND RESULTS: This was a single-centre, retrospective study with a median follow-up of 365 days. From January 2011 to December 2015, we studied 69 patients with Group 2 PH [age, 61.5 ± 13.0 (standard deviation) years; male:female, 49:20; left ventricular ejection fraction, 50.1 ± 20.4%; mean pulmonary arterial pressure, ≥25 mmHg; and pulmonary arterial wedge pressure (PAWP), >15 mmHg]. No adverse events were observed after NO inhalation. Thirty-four patients with Group 2 PH showed increased PAWP (ΔPAWP: 3.26 ± 2.22 mmHg), while the remaining 35 patients did not (ΔPAWP: -2.11 ± 2.29 mmHg). Multivariate analysis revealed that increased PAWP was the only significant predictor of all-cause death or hospitalization for heart failure (HF) after 1 year (hazard ratio 4.35; 95% confidence interval, 1.27-14.83; P = 0.019). The acute response of PAWP to NO differed between HF with preserved and reduced ejection fractions. CONCLUSIONS: Patients with Group 2 PH were tolerant of the inhaled NO test. NO-induced PAWP is a novel prognostic indicator.

A case of fulminant type 1 diabetes and protein C deficiency complicated by deep vein thrombosis.

A 25-year-old man was diagnosed with diabetic ketoacidosis (DKA) at the onset of fulminant type 1 diabetes. After acute-phase DKA treatment including placement of a central venous catheter, a massive deep vein thrombosis (DVT) and pulmonary embolism (PE) were detected on hospital day 15. His protein C (PC) activity and antigen levels were low even 33 days after completing the DKA treatment, indicating partial type I PC deficiency. Severe PC dysfunction, due to overlapping of partial PC deficiency and hyperglycemia-induced PC suppression, concomitant with dehydration and catheter treatment, may have induced the massive DVT with PE. This case suggests that anti-coagulation therapy should be combined with acute-phase DKA treatment in patients with PC deficiency, even those who have been asymptomatic. As patients with partial PC deficiency should perhaps be included among those with severe DVT complications of DKA, venous thrombosis should always be considered as a potential complication of DKA.

18 F-FDG PET/CT Imaging Post Heart Transplantation Depicts High Accumulation at Sites of Previous Ventricular Assist Device Insertion.

ABSTRACT: A 37-year-old man with previous heart transplantation for dilated cardiomyopathy underwent screening for malignancy under posttransplantation immunosuppression. 18 F-FDG PET/CT revealed uptake in 2 peritoneal sites of the pericardium that corresponded to the insertion sites of a left ventricular assist device that was used before transplantation. Additional abnormal uptake in the right axillary artery, aortic arch, and left femoral artery corresponded to the insertion sites for arterial inflow during cardiopulmonary bypass. Knowledge that FDG accumulation may occur at the insertion sites of an extracorporeal-circulation device enables unnecessary tests to be avoided.

Update on the roles of imaging in the management of chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH), classified as group 4 pulmonary hypertension (PH), is caused by stenosis and obstruction of the pulmonary arteries by organized thrombi that are incompletely resolved after acute pulmonary embolism. The prognosis of patients with CTEPH is poor if untreated; however, in expert centers with multidisciplinary teams, a treatment strategy for CTEPH has been established, dramatically improving its prognosis. CTEPH is currently not a fatal disease and is the only curable form of PH. Despite these advances and the establishment of treatment approaches, early diagnosis is still challenging, especially for non-experts, for several reasons. One of the reasons for this is insufficient knowledge of the various diagnostic imaging modalities, which are essential in the clinical practice of CTEPH. Imaging modalities should detect the following pathological findings: lung perfusion defects, thromboembolic lesions in pulmonary arteries, and right ventricular remodeling and dysfunction. Perfusion lung scintigraphy and catheter angiography have long been considered gold standards for the detection of perfusion defects and assessment of vascular lesions, respectively. However, advances in imaging technology of computed tomography and magnetic resonance imaging have enabled the non-invasive detection of these abnormal findings in a single examination. Cardiac magnetic resonance (CMR) is the gold standard for evaluating the morphology and function of the right heart; however, state-of-the-art techniques in CMR allow the assessment of cardiac tissue characterization and hemodynamics in the pulmonary arteries. Comprehensive knowledge of the role of imaging in CTEPH enables appropriate use of imaging modalities and accurate image interpretation, resulting in early diagnosis, determination of treatment strategies, and appropriate evaluation of treatment efficacy. This review summarizes the current roles of imaging in the clinical practice for CTEPH, demonstrating the characteristic findings observed in each modality.

Usefulness of cardiac magnetic resonance for early detection of cancer therapeutics-related cardiac dysfunction in breast cancer patients.

BACKGROUND: Prognosis of breast cancer patients has been improved along with the progress in cancer therapies. However, cancer therapeutics-related cardiac dysfunction (CTRCD) has been an emerging issue. For early detection of CTRCD, we examined whether native T1 mapping and global longitudinal strain (GLS) using cardiac magnetic resonance (CMR) and biomarkers analysis are useful. METHODS: We prospectively enrolled 83 consecutive chemotherapy-naïve female patients with breast cancer (mean age, 56 ± 13 yrs.) between 2017 and 2020. CTRCD was defined based on echocardiography as left ventricular ejection fraction (LVEF) below 53% at any follow-up period with LVEF>10% points decrease from baseline after chemotherapy. To evaluate cardiac function, CMR (at baseline and 6 months), 12­lead ECG, echocardiography, and biomarkers (at baseline and every 3 months) were evaluated. RESULTS: A total of 164 CMRs were performed in 83 patients. LVEF and GLS were significantly decreased after chemotherapy (LVEF, from 71.2 ± 4.4 to 67.6 ± 5.8%; GLS, from -27.9 ± 3.9 to -24.7 ± 3.5%, respectively, both P < 0.01). Native T1 value also significantly elevated after chemotherapy (from 1283 ± 36 to 1308 ± 39 msec, P < 0.01). Among the 83 patients, 7 (8.4%) developed CTRCD. Of note, native T1 value before chemotherapy was significantly higher in patients with CTRCD than in those without it (1352 ± 29 vs. 1278 ± 30 msec, P < 0.01). The multivariable logistic regression analysis revealed that native T1 value was an independent predictive factor for the development of CTRCD [OR 2.33; 95%CI 1.15-4.75, P = 0.02]. CONCLUSIONS: These results indicate that CMR is useful to detect chemotherapy-related myocardial damage and predict for the development of CTRCD in breast cancer patients.

Identification of the Novel Variants in Patients With Chronic Thromboembolic Pulmonary Hypertension.

Background Although chronic thromboembolic pulmonary hypertension (CTEPH) and acute pulmonary embolism (APE) share some clinical manifestations, a limited proportion of patients with CTEPH have a history of APE. Moreover, in histopathologic studies, it has been revealed that pulmonary vasculature lesions similar to pulmonary arterial hypertension existed in patients with CTEPH. Thus, it remains unknown whether these 3 disorders also share genetic backgrounds. Methods and Results Whole exome screening was performed with DNA isolated from 51 unrelated patients with CTEPH of Japanese ancestry. The frequency of genetic variants associated with pulmonary arterial hypertension or APE in patients with CTEPH was compared with those in the integrative Japanese Genome Variation Database 3.5KJPN. Whole exome screening analysis showed 17 049 nonsynonymous variants in patients with CTEPH. Although we found 6 nonsynonymous variants that are associated with APE in patients with CTEPH, there was no nonsynonymous variant associated with pulmonary arterial hypertension. Patients with CTEPH with a history of APE had nonsynonymous variants of F5, which encodes factor V. In contrast, patients with CTEPH without a history of APE had a nonsynonymous variant of THBD, which encodes thrombomodulin. Moreover, thrombin-activatable fibrinolysis inhibitor, which is one of the pathogenic proteins in CTEPH, was significantly more activated in those who had the variants of THBD compared with those without it. Conclusions These results provide the first evidence that patients with CTEPH have some variants associated with APE, regardless of the presence or absence of a history of APE. Furthermore, the variants might be different between patients with CTEPH with and without a history of APE.

Beneficial effects of riociguat on hemodynamic responses to exercise in CTEPH patients after balloon pulmonary angioplasty - A randomized controlled study.

BACKGROUND: Although balloon pulmonary angioplasty (BPA) improves symptoms and pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH), the effects of riociguat on hemodynamics and exercise capacity in patients after BPA remain to be elucidated. METHODS AND RESULTS: This study was a single-center, prospective, randomized, open-label trial. From November 2015 to November 2018, we prospectively examined 21 patients with CTEPH (65 ± 9 years old, M/F 2/19) who showed hemodynamic improvement with mean pulmonary arterial pressure (mPAP) < 30 mmHg after BPA without any vasodilators. We performed hemodynamic evaluation and expired gas analysis both at rest and during exercise in supine position using cycle ergometer. After right heart catheterization during exercise, they were randomly assigned to 2 groups with minimized method, using age, sex, and resting mPAP; riociguat (N = 10) and control (N = 11) groups. After 6 months, exercise capacity evaluated by 6-min walk distance and cardiopulmonary exercise testing, and resting hemodynamic parameters were comparable in both groups. However, cardiac output (CO) (6.0 ± 1.7-7.4 ± 1.6, P < 0.01) and pulmonary vascular resistance (4.8 ± 1.8-3.2 ± 0.7 Wood units, P = 0.02) at peak workload were significantly improved in the riociguat group as compared with the control group. The slope of linearized mPAP-CO relationship was significantly decreased in the riociguat group [14.5 (7.8, 14.7) to 6.41 (5.1, 11.4), P < 0.01] but not in the control group. CONCLUSIONS: These results indicate that riociguat exerts beneficial effects on hemodynamic response to exercise in CTEPH patients even after hemodynamic improvement by BPA.

4D-flow MRI assessment of blood flow before and after endovascular intervention in a patient with pulmonary hypertension due to isolated pulmonary artery involvement in large vessel vasculitis.

A 43-year-old woman presented with dyspnea during exertion and lower leg edema. Contrast-enhanced computed tomography images demonstrated extensive proximal narrowing in the right main pulmonary artery with thickening and enhancement. Right heart catheterization revealed the presence of precapillary pulmonary hypertension with a mean pulmonary arterial pressure of 45 mm Hg. The patient was diagnosed with large-vessel vasculitis with isolated pulmonary artery involvement. Takayasu's arteritis was suspected, but histological examination was not performed. Several sessions of pulmonary arterial intervention were stratified for the right main pulmonary artery. After treatment, mean pulmonary arterial pressure had decreased to 22 mm Hg with improvement in symptoms. Thoracic 4D-flow magnetic resonance imaging was performed before and after intervention to evaluate the volume flow rates of pulmonary arteries. The rates increased at the inlet of the right pulmonary artery (before: 23 mL/s vs after: 47.5 mL/s) and the main pulmonary artery (before: 71.2 mL/s vs after: 82.5 mL/s), and decreased at the inlet of the left pulmonary artery (before: 46.2 mL/s vs after: 31.7 mL/s). The split ratio of volume flow rate between the right and left pulmonary arteries improved after treatment (before. right:left = 33.1:66.9; after, right:left = 60.0:40.0), approaching normal values. This report quantitatively describes perioperative hemodynamic changes in a patient with pulmonary hypertension using 4D-flow magnetic resonance imaging. Stent placement for stenosis in the right pulmonary artery resulted in an increase in overall pulmonary blood flow and also improved blood flow balance between the right and the left pulmonary arteries.

Cyclophilin A as a biomarker for the therapeutic effect of balloon angioplasty in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Although cardiac troponin and natriuretic peptide have been shown to decrease after balloon pulmonary angioplasty (BPA) with improved right ventricular afterload in chronic thromboembolic pulmonary hypertension (CTEPH), biomarkers to evaluate the effects of BPA independently of heart failure status remain to be developed. METHODS: In 39 consecutive CTEPH patients including 31 who underwent BPA, we measured plasma levels of cyclophilin A (CyPA), which we demonstrated is secreted from pulmonary vascular smooth muscle cells in response to mechanical stretch and hypoxia. RESULTS: CyPA levels were elevated in CTEPH patients (12.7, IQR: 7.6-16.0) compared with 8 thromboembolic controls with a history of venous thromboembolism (4.9, IQR: 2.4-11.2) or 18 healthy controls (4.1, IQR: 2.4-6.8) (both p< 0.05) and were linearly correlated with mean pulmonary arterial pressure (r=0.50, p = 0.0003) and pulmonary vascular resistance (r=0.32, p= 0.026). BPA reduced CyPA levels and tended to lower brain-type natriuretic peptide (BNP) levels (p< 0.01 and p = 0.07). When comparing the changes in CyPA before and after BPA in the two subgroups with higher (≥35pg/mL) and normal (<35pg/mL) BNP at baseline, CyPA decreased both in patients with higher BNP and those with normal BNP (both p< 0.05). In contrast, BNP decreased only in patients with higher BNP (p< 0.05). Also, CyPA decreased both in patients with lower (<25 kg/m2) and higher (≥25kg/m2) body mass index (BMI) at baseline (both p<0.05), whereas BPA tended to reduce BNP in patients with lower BMI (p = 0.12) but not in those with higher BMI (p = 0.55). CONCLUSIONS: CyPA could be a useful biomarker to evaluate the effects of BPA even in patients with normal BNP or high BMI.

Identification of Adipsin as a Novel Prognostic Biomarker in Patients With Coronary Artery Disease.

Background Circulating proteins are exposed to vascular endothelial layer and influence their functions. Among them, adipsin is a member of the trypsin family of peptidases and is mainly secreted from adipocytes, monocytes, and macrophages, catalyzing the rate-limiting step of the alternative complement pathway. However, its pathophysiological role in cardiovascular disease remains to be elucidated. Here, we examined whether serum adipsin levels have a prognostic impact in patients with coronary artery disease. Methods and Results In 370 consecutive patients undergoing diagnostic coronary angiography, we performed a cytokine array analysis for screening serum levels of 50 cytokines/chemokines and growth factors. Among them, classification and regression analysis identified adipsin as the best biomarker for prediction of their long-term prognosis (median 71 months; interquartile range, 55-81 months). Kaplan-Meier curve showed that higher adipsin levels (≥400 ng/mL) were significantly associated with all-cause death (hazard ratio [HR], 4.2; 95% CI, 1.7-10.6 [P<0.001]) and rehospitalization (HR, 2.4; 95% CI, 1.7-3.5 [P<0.001]). Interestingly, higher high-sensitivity C-reactive protein levels (≥1 mg/L) were significantly correlated with all-cause death (HR, 3.2; 95% CI, 1.7-5.9 [P<0.001]) and rehospitalization (HR, 1.5, 95% CI, 1.1-1.9 [P<0.01]). Importantly, the combination of adipsin (≥400 ng/mL) and high-sensitivity C-reactive protein (≥1 mg/L) was more significantly associated with all-cause death (HR, 21.0; 95% CI, 2.9-154.1 [P<0.001]). Finally, the receiver operating characteristic curve demonstrated that serum adipsin levels predict the death caused by acute myocardial infarction in patients with coronary artery disease (C-statistic, 0.847). Conclusions These results indicate that adipsin is a novel biomarker that predicts all-cause death and rehospitalization in patients with coronary artery disease, demonstrating the novel aspects of the alternative complementary system in the pathogenesis of coronary artery disease.

Diagnostic and Prognostic Significance of Serum Levels of SeP (Selenoprotein P) in Patients With Pulmonary Hypertension.

OBJECTIVE: Despite the recent progress in upfront combination therapy for pulmonary arterial hypertension (PAH), useful biomarkers for the disorder still remain to be developed. SeP (Selenoprotein P) is a glycoprotein secreted from various kinds of cells including pulmonary artery smooth muscle cells to maintain cellular metabolism. We have recently demonstrated that SeP production from pulmonary artery smooth muscle cells is upregulated and plays crucial roles in the pathogenesis of PAH. However, it remains to be elucidated whether serum SeP levels could be a useful biomarker for PAH. Approach and Results: We measured serum SeP levels and evaluated their prognostic impacts in 65 consecutive patients with PAH and 20 controls during follow-up (mean, 1520 days; interquartile range, 1393-1804 days). Serum SeP levels were measured using a newly developed sol particle homogeneous immunoassay. The patients with PAH showed significantly higher serum SeP levels compared with controls. Higher SeP levels (cutoff point, 3.47 mg/L) were associated with the outcome (composite end point of all-cause death and lung transplantation) in patients with PAH (hazard ratio, 4.85 [1.42-16.6]; P<0.01). Importantly, we found that the absolute change in SeP of patients with PAH (ΔSeP) in response to the initiation of PAH-specific therapy significantly correlated with the absolute change in mean pulmonary artery pressure, pulmonary vascular resistance (ΔPVR), and cardiac index (ΔCI; R=0.78, 0.76, and -0.71 respectively, all P<0.0001). Moreover, increase in ΔSeP during the follow-up predicted poor outcome of PAH. CONCLUSIONS: Serum SeP is a novel biomarker for diagnosis and assessment of treatment efficacy and long-term prognosis in patients with PAH.

ADAMTS8 Promotes the Development of Pulmonary Arterial Hypertension and Right Ventricular Failure: A Possible Novel Therapeutic Target.

RATIONALE: Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling with aberrant pulmonary artery smooth muscle cells (PASMCs) proliferation, endothelial dysfunction, and extracellular matrix remodeling. OBJECTIVE: Right ventricular (RV) failure is an important prognostic factor in PAH. Thus, we need to elucidate a novel therapeutic target in both PAH and RV failure. METHODS AND RESULTS: We performed microarray analysis in PASMCs from patients with PAH (PAH-PASMCs) and controls. We found a ADAMTS8 (disintegrin and metalloproteinase with thrombospondin motifs 8), a secreted protein specifically expressed in the lung and the heart, was upregulated in PAH-PASMCs and the lung in hypoxia-induced pulmonary hypertension (PH) in mice. To elucidate the role of ADAMTS8 in PH, we used vascular smooth muscle cell-specific ADAMTS8-knockout mice (ADAMTSΔSM22). Hypoxia-induced PH was attenuated in ADAMTSΔSM22 mice compared with controls. ADAMTS8 overexpression increased PASMC proliferation with downregulation of AMPK (AMP-activated protein kinase). In contrast, deletion of ADAMTS8 reduced PASMC proliferation with AMPK upregulation. Moreover, deletion of ADAMTS8 reduced mitochondrial fragmentation under hypoxia in vivo and in vitro. Indeed, PASMCs harvested from ADAMTSΔSM22 mice demonstrated that phosphorylated DRP-1 (dynamin-related protein 1) at Ser637 was significantly upregulated with higher expression of profusion genes (Mfn1 and Mfn2) and improved mitochondrial function. Moreover, recombinant ADAMTS8 induced endothelial dysfunction and matrix metalloproteinase activation in an autocrine/paracrine manner. Next, to elucidate the role of ADAMTS8 in RV function, we developed a cardiomyocyte-specific ADAMTS8 knockout mice (ADAMTS8ΔαMHC). ADAMTS8ΔαMHC mice showed ameliorated RV failure in response to chronic hypoxia. In addition, ADAMTS8ΔαMHC mice showed enhanced angiogenesis and reduced RV ischemia and fibrosis. Finally, high-throughput screening revealed that mebendazole, which is used for treatment of parasite infections, reduced ADAMTS8 expression and cell proliferation in PAH-PASMCs and ameliorated PH and RV failure in PH rodent models. CONCLUSIONS: These results indicate that ADAMTS8 is a novel therapeutic target in PAH.

Beneficial Effects of Imatinib in a Patient with Suspected Pulmonary Veno-Occlusive Disease.

Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary hypertension (PH). The prognosis of PVOD patients remains poor, since no effective medical therapy is yet available. Imatinib is a tyrosine kinase inhibitor specific for platelet-derived growth factor receptor and is expected as a treatment option for pulmonary arterial hypertension (PAH). Recently, it has been reported that imatinib improved functional capacity of a patient with PVOD. We here report a patient with suspected PVOD who has been successfully treated with imatinib and is alive for 6 years after diagnosis. A 57-year-old woman was admitted to a hospital for severe dyspnea. Echocardiography suggested the presence of PH, because tricuspid regurgitation pressure gradient was elevated. The patient was then transferred to our hospital by an ambulance ahead of schedule due to fever and worsening dyspnea. Because the patient had no left heart disease, we diagnosed that she had PAH associated with severe right heart failure. We immediately started treatment with nitric oxide (NO) for her severe hypoxia; however, it caused pulmonary edema. We suspected PVOD from CT characteristics and pulmonary edema after PAH-targeted vasodilator therapy, and then started oral imatinib treatment. In response to imatinib, her pulmonary edema gradually improved. Since then, the patient has been alive for 6 years with imatinib and pulmonary vasodilators. At present, lung transplantation is the only effective therapy for PVOD with limited availability. We therefore propose that imatinib may be a treatment option for PVOD and a bridge to lung transplantation.

Identification of Novel Therapeutic Targets for Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are fatal diseases; however, their pathogenesis still remains to be elucidated. We have recently screened novel pathogenic molecules and have performed drug discovery targeting those molecules. Pulmonary artery smooth muscle cells (PASMCs) in patients with PAH (PAH-PASMCs) have high proliferative properties like cancer cells, which leads to thickening and narrowing of distal pulmonary arteries. Thus, we conducted a comprehensive analysis of PAH-PASMCs and lung tissues to search for novel pathogenic proteins. We validated the pathogenic role of the selected proteins by using tissue-specific knockout mice. To confirm its clinical significance, we used patient-derived blood samples to evaluate the potential as a biomarker for diagnosis and prognosis. Finally, we conducted a high throughput screening and found inhibitors for the pathogenic proteins.

Selenoprotein P Promotes the Development of Pulmonary Arterial Hypertension: Possible Novel Therapeutic Target.

BACKGROUND: Excessive proliferation and apoptosis resistance of pulmonary artery smooth muscle cells (PASMCs) are key mechanisms of pulmonary arterial hypertension (PAH). Despite the multiple combination therapy, a considerable number of patients develop severe pulmonary hypertension (PH) because of the lack of diagnostic biomarker and antiproliferative therapies for PASMCs. METHODS: Microarray analyses were used to identify a novel therapeutic target for PAH. In vitro experiments, including lung and serum samples from patients with PAH, cultured PAH-PASMCs, and high-throughput screening of 3336 low-molecular-weight compounds, were used for mechanistic study and exploring a novel therapeutic agent. Five genetically modified mouse strains, including PASMC-specific selenoprotein P (SeP) knockout mice and PH model rats, were used to study the role of SeP and therapeutic capacity of the compounds for the development of PH in vivo. RESULTS: Microarray analysis revealed a 32-fold increase in SeP in PAH-PASMCs compared with control PASMCs. SeP is a widely expressed extracellular protein maintaining cellular metabolism. Immunoreactivity of SeP was enhanced in the thickened media of pulmonary arteries in PAH. Serum SeP levels were also elevated in patients with PH compared with controls, and high serum SeP predicted poor outcome. SeP-knockout mice ( SeP-/-) exposed to chronic hypoxia showed significantly reduced right ventricular systolic pressure, right ventricular hypertrophy, and pulmonary artery remodeling compared with controls. In contrast, systemic SeP-overexpressing mice showed exacerbation of hypoxia-induced PH. Furthermore, PASMC-specific SeP-/- mice showed reduced hypoxia-induced PH compared with controls, whereas neither liver-specific SeP knockout nor liver-specific SeP-overexpressing mice showed significant differences with controls. Altogether, protein levels of SeP in the lungs were associated with the development of PH. Mechanistic experiments demonstrated that SeP promotes PASMC proliferation and resistance to apoptosis through increased oxidative stress and mitochondrial dysfunction, which were associated with activated hypoxia-inducible factor-1α and dysregulated glutathione metabolism. It is important to note that the high-throughput screening of 3336 compounds identified that sanguinarine, a plant alkaloid with antiproliferative effects, reduced SeP expression and proliferation in PASMCs and ameliorated PH in mice and rats. CONCLUSIONS: These results indicate that SeP promotes the development of PH, suggesting that it is a novel biomarker and therapeutic target of the disorder.